On 2017-07-09 o 15:08, Pat writes:

understanding regarding electromagnetic waves is you can't have one
without the other.

Yes, every transmitting antenna creates perturbance that spreads around
as electromagnetic (EM) wave with electric and magnetic component but...
In the _near field_, magnetic antenna creates mainly the Magnetic
component of the field and Electric antenna (in ex. dipole) creates
electric field. The same goes to receiving. Shielded magnetic loop is
quite deaf to M component of the EM field.

(Un)fortunately most of the local noise sources create perturbance in E
field. Therefore chances are that magnetic loop will be in some degree
immune to them. The other noise sources may or may not be in the near
field range but the furher away they are the less they add to the total
noise level.

Of course you've read this?
https://en.wikipedia.org/wiki/Near_and_far_field

RF propogates through space my having the moving
electric field create a moving magnetic field which then creates a new
electric field, etc, etc. How can one exist without the other?

Here's a quote from the ad, "The MFJ-1886 drastically reduces noise
and interference by receiving the magnetic field and rejecting the
electric field". How can a varying electric field from a noise source
not also create a corresponding magnetic field? Is this a near-field
/ far-field thing?

Pat